Blood pressure (BP) control is a key component of diabetes management. BP control in patients with diabetes was assessed across 4 Colorado health plans. BP was obtained through retrospective chart reviews, and BP control was defined as <130/80 mm Hg. The study included 1445 diabetic patients in 2004 and 1423 diabetic patients in 2005. BP control did not improve significantly from 2004 to 2005; in 2004, 33.1% had controlled BP, compared with 35.2% in 2005. Women were more likely to have controlled BP than men, and younger patients were more likely to have controlled BP than older patients. Two of the 4 plans showed significant improvement in BP control, whereas the proportion of patients with BP controlled declined in 2 health plans. More aggressive disease management and pharmacologic treatment of blood pressure is needed to improve the cardiovascular health of patients with diabetes. (Am J Med Qual 2008;23:201-207)